Very rare 1941 proof set. If you’re reading this, you already know how hard they are to find. Feel free to ask any questions you might have.. The product is a 1941 US Proof Set containing 5 coins in a Capitol plastic holder. The set includes proof coins with a fineness of 0.9, struck at the Philadelphia Mint. It is ungraded and certified by the U. The coins are uncirculated and were minted in the United States.